I rooted thé nexus s, installed rsap trial v1.2 with System files. The phone was visible, the pairing worked but It disconnect after 2 seconds.i made a factory reset and tried without installing System file and the résult is the same.I tried to make a log but i don't know where the files are?

Please post the version of your premium car kit ... Just enter *#0000#If it is 6.00 or later it works normally. Try to power off the phone after initial pairing.Older Versions have problems with all smart-phones. Try to get an upgrade (it is the same Hardware 015) for Version 3. or 4.